The new drug to treat aggressive prostate cancer could potentially treat up to 80% of patients with the deadly form of the disease that is currently resistant to chemotherapy. The drug is called abiraterone.
Abiraterone prevents the cancer from making its own hormones that allow the cancer cells to survive.
British and American patients participating in the study showed declines in prostate specific antigen levels and their tumors shrank, even when the cancer spread to other parts of the body.
Scientists also believe the technique could be effective on other tumors including breast and bowel cancers.
Researchers say they have made a major step forward in the treatment of end-stage prostate cancer patients but the findings need to be confirmed in larger trials.
Trial results are published in the Journal of Clinical Oncology.